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Proceedings Paper

Direct Phase Measurement Of Aspheric Surface Contours
Author(s): Katherine Creath; James C. Wyant
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Paper Abstract

Two-wavelength holography and phase-shifting interferometry are combined to measure aspheric surface contours with a variable sensitivity. In this technique, the surface is effectively tested at a synthesized longer equivalent wavelength λeq = λaλb|λa - λb| using measurements made at wavelengths λa and λb where the difference of the phases measured for λa and λb yields the modulo 2π phase at λeq. A mask of point apertures is placed over the detector array in order to resolve closely spaced fringes. This technique has an rms repeatability of λeq/100. Limits to this technique are discussed and results are shown.

Paper Details

Date Published: 3 November 1986
PDF: 6 pages
Proc. SPIE 0645, Optical Manufacturing, Testing and Aspheric Optics, (3 November 1986); doi: 10.1117/12.964494
Show Author Affiliations
Katherine Creath, WYKO Corporation (United States)
James C. Wyant, WYKO Corporation (United States)


Published in SPIE Proceedings Vol. 0645:
Optical Manufacturing, Testing and Aspheric Optics
Gregory M. Sanger, Editor(s)

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